DE69529832T2 - AQUEOUS METAL CLEANER - Google Patents

Abstract

A composition and method for cleaning metal and for inhibiting corrosion of metal. The composition is composed of an alkaline metal salt, a surfactant, and a corrosion inhibitor with a pH in the range from about 7.5 to less than 10, and is preferably silicate free. The corrosion inhibitor is provided in the form of a combination of a triazole compound and an alkali metal borate. The composition can be employed to clean metal surfaces as an aqueous concentrate or aqueous solution.

Description

The present extension relates generally aqueous metal cleaning compositions. This concerns in particular Invention aqueous metal cleaning compositions in so-called parts washers Advantage can be used and in particular the invention relates to parts cleaners which are particularly adapted to professional and semi-professional artisans, as well as homeowners, farmers, ranchers, home improvement and to be used by other such users.

Parts washers are known to the person skilled in the art different embodiments as devices known the big ones Benefits for Artisans and other people is in different professions work, especially for such People working in industrial plants or in maintenance and repair services work. Earlier the development of parts washers was based on trying one reasonable comfort in use and good cleaning properties sure. Many petrol stations and repair shops had soaking containers Hot containers, or Parts cleaner of the immersion type, usually in more or less sophisticated design.

U.S. 3,522,814 to Olson to the Safety-Kleen Corporation, describes a new one Concept for Parts washer, than a parts washer construction describes the construction among other new features includes, which is specially adapted to an extremely fast and simple machine service. It was afterwards established an entire industry, based on the concept of a parts washer designed like this was that he was less specialized, if at all, by workers Training could be operated economically and effectively. you discovered that among petrol station and repair shop owners, car dealers and industrial plant operators gave an enormous market for parts washers, which are safe and without interruptions, either through downtime or physical disorders, could be operated.

The ideal parts washer is reliable, safe, quiet and effective to use, free from environmental influences and, perhaps most importantly, it can be operated easily as described above. While the parts washer described in U.S. 3,522,814 achieved phenomenal commercial success in the market, various improvements have been made and described in several U.S. patents, including U.S. 4,096,873 US 4,160,603 , U.S. 4,261,378, U.S. 4,462,415 and U.S. 4,637,413.

The in the above patent The device described by Olson was very successful industrially, since they are a parts washer provided the over had an economical and risk-free mode of operation by Parts to be cleaned are subjected to a circulating stream of solvent were. When operating the device described in the Olson patent a solvent through a pump from a storage container into a Sink containing the parts to be cleaned circulates. A stream of solvent is directed against the parts and flows in through the sink Filter medium for recycling in the storage vessel. in case of a The washer described in U.S. Patent No. 3,522,814 can fire automatically a hood over the Close sink, to minimize their effect.

Although the scrubber of U.S. Patent No. 3,522,814 provides greatly improved operating characteristics during cleaning, was found to be beneficial under certain conditions such as when an exceptionally large amount foreign material adheres to the elements to be washed, the parts for one Time in a bath of a solvent or another liquid soak. Such a soaking is used in the known techniques generally achieved by putting the parts in a liquid immersed in an open vessel be, from the open container undesirable solvent vapors in the environment can evaporate, which leads to a cost-intensive consumption of the liquid and the risk of an uncontrolled There is fire or splashing. Preventing such an uncontrolled Soaking in an open jar more importantly in light of numerous government regulations that regulate the use of substances in the form of solvents, such as the O.S.H.A .. Therefore, in the above US 4,261,378 provided a very advantageous accessory, the one enables very effective washing of parts with one drain, as disclosed in U.S. Patent No. 3,522,814, with the alternative mode of operation a very effective and safe Soaking device.

That disclosed in US 4,261,378 Accessory overcomes the above problems by allowing a conventional one washer operate in normal circulation mode without substantial soaking, with the additional Advantage, a lot of solvent selectively withheld in a sink for soaking application. That through the accessory enabled Soaking is achieved by a device that allows the escape of vapors into the environment and the costly evaporation of the cleaning solvent prevents and at the same time the risk of fire and others accidents minimized. additionally improved soaking with the accessory is achieved by a predetermined one Solvent level above the to be cleaned parts is maintained, with constant circulation of the solvent.

Existing solvents, with special additives or without special additives, are suitable to achieve a good cleaning of most dirty, greasy mechanical parts. A large number of these solvents are used to remove contamination from metallic surfaces. This Wash solvent formulations generally include various halogenated hydrocarbons and non-halogenated hydrocarbons which are common in the industry for cleaning and degreasing metal surfaces, the amount and success of these wash solvent formulations generally depending on the degree of purity of the resulting surfaces is required.

Lately the ones used previously are various hydrocarbon-containing and halogenated hydrocarbons containing metal cleaning compositions with regard to the materials used have been checked, and it is particularly the environmental impact from use of different materials have been studied. This has been particular investigated where cleaning parts in a closed environment carried out such as in repair shops or even at home in terms of close human contact. Even adding Devices for parts washers, which is splashing, fire hazard and excessive evaporation of the cleaning solvent can reduce is not enough to alleviate concerns about the environment.

Although the halogenated hydrocarbon solvents, such as chlorofluorocarbons (CFCs) and trichloromethane, Methylene chloride and trichloroethane (methyl chloroform) in the industry Metal cleaning are widely used, their safety and security the waste disposal problems associated with environmental and cost factors negative aspects of their use. A worldwide ban and a US ban on most halogenated hydrocarbon solvents is by the Montreal Protocol, the regulation for clean Air and administrative and district directives soon in prospect.

The non-halogenated hydrocarbon solvents, such as toluene, the Stoddard solvent and the like are organic compounds such as ketones and alcohols flammable, on the other hand, usually have a high Vaporizability and the possibility recycling for continuous use is questionable. As a result of these factors and the unfavorable Security aspects and the environmental and cost factors include this Group of solvents in a category for practical applications is unattractive. Most organic solvent are fleeting organic compounds that pollute the atmosphere, education promote toxic ozone on the ground and be added to the greenhouse gas supply.

To the various negative aspects the known chemical washing and degreasing systems has been eliminated therefore suggested that an aqueous Detergent system is used so that the negative environmental and Health effects of solvent cleaning systems of the prior art overcome become. aqueous Unfortunately, cleaning systems are not without their own problems with a view to their use in metal cleaning systems, including the Use in the parts washer described above. For example certain watery Cleaner extremely alkaline and have pH values of 13 and higher, such as sodium hydroxide or include organic solvents, such as alkanolamines, ethers, alcohols or glycols. In addition to being highly corrosive, they are strong alkaline solutions very toxic and dangerous to handle and require extreme security measures to keep in touch with to avoid the skin. With watery Cleaners that contain organic solvents included are those mentioned above Problems related to toxicity or the environment. On the other hand, it is very difficult to use an aqueous cleaning solution to maintain a moderate pH with which fats and oils can be removed effectively let's including the metals Dirt metal motor parts and they are not corrosive to the Is metal substrates.

The US 5,230,824 discloses an aqueous metal cleaning preparation for removing oil, dirt and grinding debris from razor blades and which comprises an alkaline agent, a chelating agent, a hydrotrope and a defoamer, together with a non-ionic surfactant. The preferred alkalinity agents include alkali metal hydroxides, alkali metal silicates and alkali metal carbonates. The non-ionic surfactant includes the ethoxylates of C ₉ -C ₁₆ tertiary thiols as described in U.S. Patent Nos. 4,575,569 and 4,931,205.

While it has been found that ethoxylated thiol-containing surfactants are very effective in aqueous solutions for removing grease from substrates, especially metal surfaces, a disadvantage of these surfactants is the very unpleasant smell that the surfactant transfers to a product, such as a concentrate to which the surfactants are added, as well as the more dilute wash solutions containing these ethoxylated thiol-containing surfactants. The unpleasant smell significantly reduces the number of products to which the ethoxylated thiol-containing surfactants can be added. This is particularly true of the parts washers described above and developed by Safety-Kleen Corporation, which have been very successful in the commercial service sector, including gas stations, repair shops and car dealers. In the typically closed environments of such commercial companies, the unpleasant smell of ethoxylated thiol-containing surfactants would not be tolerated and their use would severely affect business operations. On the other hand, the excellent fat-removing properties of this surfactant make it The substances in aqueous cleaning systems are particularly useful for parts washer devices and processes for metal cleaning.

It is therefore an object of the present Ending, a watery provide metal cleaning composition which is effective in Remove grease, oil and other dirt from a metal surface, without being too corrosive of the substrate and irritating to human skin to be.

Another object of the invention is a watery to provide metal cleaning composition that is effective in Parts washers immersion and impact type can be used, and so effectively Fat, oil and other contaminants removed from metal parts and the safe is in use and not harmful to the environment during use and at disposal.

Yet another object of the present Invention is an aqueous metal cleaning composition to provide an ethoxylated thiol-containing surface-active Contains substance and is formulated so that it has the unpleasant smell that comes with the surface active Substance is extraordinary reduced, if not eliminated.

Yet another object of the present Invention is an aqueous metal cleaning composition to provide an ethoxylated thiol-containing surface-active Contains substance, not the one with the surfactant Substance has an unpleasant smell and is therefore effective in parts washers from Immersion and impact type is and in the relatively closed business operations can be used in which such parts washers are used.

Summary the invention

The above tasks and others Tasks are performed according to the present Invention solved, by a watery alkaline metal cleaning solution is provided that has a pH lower than 12, but a sufficiently high pH to effectively remove dirt, grease and oil from metals and which includes an ethoxylated thiol-containing surfactant which the cleaning properties of the aqueous alkaline solution are extraordinary increases but the solution does not give off an unpleasant smell. In contrast to halogenated solvents or hydrocarbon solvents The prior art is the aqueous alkaline solution Invention environmentally safe to use and has only low Quantities of organic substances that do not evaporate easily, and is safe to dispose of.

The aqueous metal cleaning composition of the present invention comprises an alkaline agent and a Combination of surface active Substances comprising an ethoxylated thiol and a nitrogenous one surfactants Substance containing the surface active with the ethoxylated thiol-containing Substance associated with unpleasant smell greatly reduced when not even eliminated. The nitrogenous surface active Substance does not reduce the effectiveness of the ethoxylated thiol in terms of its ability Remove grease from metal substrates. In addition, the cleaning composition emulsifies this invention the oil and the grease that is removed from the metal surface is not without further so that the fat and oil skimmed off of the wash-bath for disposal or otherwise light can be separated. As a result, the cleanability of the watery Cleaner for maintain continued reuse.

The aqueous cleaning preparation This invention is particularly effective when used in parts washer systems is used, such as those made by Safety-Kleen Corporation have been developed that have become extraordinarily successful commercially are independent whether it is manually controlled parts washers or those from automatic type. The cleaning compositions and the resulting ones manufactured aqueous Cleaning solutions are particularly useful in washing systems that are in relatively closed systems business operations can be found, for example in petrol stations and repair shops. The aqueous metal cleaning composition of this invention is in such Parts washing systems can be used particularly advantageously since such compositions are environmentally compatible and physically safe to use in relatively closed environments and are handled, stored and disposed of without any environmental problems can, like they are otherwise from volatile and toxic organic substances are caused or without the dangers that of the previously proposed extremely highly alkaline aqueous Compositions run out.

Short description the drawing

The figure is a graph of cleaning effectiveness, the inventive composition with known commercial cleaners compares.

detailed Description of the invention

The aqueous cleaning compositions of the present invention include an alkaline agent and a Combination of two surface active Substances, one being an ethoxylated thiol, are very effective in the removal of fat and oil of metal substrates and is a nitrogenous surfactant Substance that surprisingly the smell associated with the ethoxylated thiol-containing surfactant Substance is extraordinary reduced and not the effectiveness of the ethoxylated thiol-containing surfactants Substance reduced. The watery alkaline metal cleaning solution a pH of at least 8.0 to less than 12, preferably less than 11 what these solutions much less dangerous in use and handling, as a highly alkaline aqueous cleaner, such as for example those made from sodium hydroxide or aqueous Alkanolamine solutions are formed. Most preferably, the aqueous alkaline cleaning solution has one pH from 8.0 to 10.0, which is an effective value for removal of dirt, grease, oil and other contaminants from the metal surface and it still allows the solutions to use, handle and dispose of without human Skin is burned or irritated. It is also preferred that the composition of this invention free of organic solvents is, including Hydrocarbon, halogenated hydrocarbon and oxygenated Hydrocarbon solvents.

The alkaline agent of the aqueous metal cleaning composition of the present invention be provided by one or more alkaline salts. suitable alkaline salts or mixtures thereof, useful for the present invention, are those that the desired can supply pH. Most convenient are sodium or potassium salts. The economical, safe ones are particularly preferred and environmentally friendly potassium and sodium carbonates and bicarbonates. The carbonate salts close a: potassium carbonate, potassium carbonate dihydrate, potassium carbonate trihydrate, Sodium carbonate, sodium carbonate decahydrate, sodium carbonate heptahydrate, Sodium carbonate monohydrate, sodium sesquicarbonate and the double salts and mixtures thereof. The bicarbonate salts include potassium bicarbonate and sodium bicarbonate and mixtures thereof. Mixtures of Carbonate and bicarbonate salts are also particularly suitable.

Although not preferred, others close suitable alkaline salts that can be used Alkali metal orthophosphates or complex phosphates. The complex Because of their ability to Water hardness ions and chelating heavy metal ions are particularly effective. The complex Close phosphates for example sodium or potassium pyrophosphate, tripolyphosphate and hexametaphosphate. More for the metal cleaning compositions Alkaline salts useful in this invention include alkali metal borates, Acetates, citrates, tartrates, succinates, silicates, phosphonates and -date.

The alkoxylated (ethoxylated) thiol-containing surfactants Substances of the present invention are nonionic surfactants Substances known and for example in US Pat. No. 4,575,569 and 4,931,205. In particular, the ethoxylated thiol prepared by adding ethylene oxide to an alkylthiol Formula R-SH, wherein R is alkyl, in the presence of an acidic or basic catalyst.

The thiol reactant, the to. Manufacture of surface active Substance is suitable and in the implementation of the present invention used includes, in the broad sense, one or more of the above mentioned Alkanthiols, which are used for the alkoxylation reaction by reaction with Suitable alkylene oxides in the presence of basic catalysts is. Alkanthiols are in the range of 6 to 30 carbon atoms for the preparation of thiol alkoxylates, for use as surface-active Medium, particularly preferred while such in the range of 7 to 20 carbon atoms is more preferred are considered, and those with 8 to 18 carbon atoms most are preferred.

The thiol reactant is suitably primary, secondary or tertiary and of a linear, branched or cyclic carbon skeleton structure. Specific examples of suitable tertiary thiols are those which have a highly branched carbon chain, obtainable via hydrosulfurization of the products of oligomerization of lower olefins, in particular dimers, trimers, tetramers and pentamers of propylenes and butylenes. Examples of secondary thiols are the lower alkanethiols, such as 2-propanethiol, 2-butanethiol and 3-pentanethiol, as well as the products of the essentially linear oligomers of ethylene which can be obtained by hydrosulfurization and which have been prepared by the oxo process. Representative but in no way limiting examples of thiols derived from ethylene oligomers include the linear carbon chain products such as 2-decanethiol, 3-decanethiol, 4-decanethiol, 5-decanethiol, 3-dodecanethiol, 5 -Dodecanethiol, 2-hexadecanethiol, 5-hexadecanethiol and 8-octadecanethiol and the products with a branched carbon chain, such as 2-methyl-4-tridecanethiol. Primary thiols are typically made from terminal olefins by hydrosulfurization under free radical conditions and include, for example: 1-butanethiol, 1-hexanethiol, 1-dodecanethiol, 1-tetradecanethiol and 2-methyl-1-tridecanethiol. Polythiol reactants that have multiple -SH groups can also be used, although monothiol reactants are preferred. Reaction components which consist essentially of one or more secondary or tertiary thiols are particularly preferred.

The surfactant can be produced are by reacting the above alkylthiols with one or several of the different alkylene oxides, their use in alkoxylation reactions is known with thiols and other compounds with active hydrogen atoms. Vicinal alkylene oxides with 2 to 4 carbon atoms are particularly preferred, including Ethylene oxide, 1,2-propylene oxide and the 1,2- and 2,3-butylene oxides. Mixtures of alkylene oxides are suitable if the product is mixed with thiol alkoxylates. For thiol alkoxylates made from ethylene or propylene oxide the very advantageous surface-active properties have been recognized been, so for this reason a special preference for a reaction component consists essentially of ethylene oxide, the most is preferred for use in the invention.

The relative amounts of thiol and Alkylene oxide reactants determine the average alkylene oxide number of the alkoxylate product. In the alkoxylated thiol-containing surfactant The substance of this invention is an adduct number in the range of 3 to 20, in particular from 3 to 15, preferred. Hence there is one Preferential execution of the invention for a molar ratio of alkylene oxide reactant to the thiol reactant in the range from 3 to 20, especially from 3 to 15. An ethoxylated dodecyl mercaptan is particularly preferred 6 ethylene oxide units. Such a surfactant is a Commercial product known as ALCODET 260, sold by Rhone-Poulenc.

The ethoxylated thiol-containing surfactant Substance in the watery Cleaning preparations of this invention, unfortunately, have one unpleasant smell that is transferred to the aqueous solution in which it is introduced. It has now been found that the addition of a nitrogenous surfactants Substance eliminates the smell of the sulfur-containing surfactant and the effectiveness of the ethoxylated thiol-containing surfactants Substance, fat and oil of metal surfaces to remove, not adversely affected. Among the useful ones nitrogen-containing non-ionic surface-active substances the following:

A surfactant of the formula R ¹ R ² R ³ N → O (amine oxide detergent), wherein R ^{1 is} an alkyl group containing 10 to 28 carbon atoms, zero to two hydroxyl groups, zero to five ether linkages, at least one half of R ^{1 is} an alkyl group which has 10 to 18 carbon atoms and has no ether linkage and each radical R ² and R ^{3 is} selected from the group consisting of alkyl radicals and hydroxyalkyl radicals containing one to three carbon atoms.

Specific examples of surfactants Close amine oxides a: dimethyldodecylamine oxide, dimethyltetradecylamine oxide; Ethylmethyltetradecyl-amine oxide, Cetyldimethylamine oxide, dimethylstearylamine oxide, cetylethylpropylamine oxide, Diethyldodecylamine oxide, diethyltetradecylamine oxide, dipropyldodecylamine oxide, Bis (2-hydroxyethyl) dodecylamine oxide, bis (2-hydroxyethyl) -3-dodecoxy-1-hydroxypropylamine oxide, (2-hydroxypropyl) methyltetradecylamine oxide, dimethyloleyamine oxide, Dimethyl- (2-hydroxydedecyl) amine oxide and the corresponding decyl, Hexadecyl and octadecyl homologues of the above compounds.

More nitrogenous surfactants Close substances ethoxylated primary Alkylamines wherein the alkyl group has 10 to 20 carbon atoms has and the amine ethoxylated with 2 to 20 ethylene oxide units is. More surface active Close substances ethoxylated long chain fatty acid amides one in which the fatty acid Has 8 to 20 carbon atoms and ethoxylates the amide group with 1 to 20 ethylene oxide units is. Furthermore, non-ionic surface-active substances can be used well, by condensing ethylene oxide with the product from the reaction can be obtained from propylene oxide and ethylenediamine. For example compounds are satisfactory, the 20 to 80 wt .-% polyoxyethylene contain and have a molecular weight of 5,000 to 11,000, resulting from the reaction of ethylene oxide groups with a hydrophobic base, which is the reaction product of the reaction of ethylenediamine and an excess Is propylene oxide, wherein the base has a molecular weight of the order of magnitude from 2,500 to 3,000.

worin n eine ganze Zahl von 1 bis 3 ist, und einem Amin mit der Formel R'-NH₂, worin R' eine lineare Alkylgruppe mit 6 bis 20 Kohlenstoffatomen ist. Der Amin-Reaktand mit der Formel R'-NH₂ schließt Alkylamine mit 6 bis 20 Kohlenstoffatomen ein; Amine abgeleitet von Naturprodukten, wie zum Beispiel Kokosnuss-Amine oder Talk-Amine destillierter Schnitte oder hydrierte Derivate solcher Fettamine. Ebenso können Mischungen von Amin-Reaktanden in dem Verfahren zur Herstellung der Pyrrolidon-Verbindungen verwendet werden. Solche Mischungen können lineare Amino-Spezies mit einer Alkylgruppe desselben Molekulargewichts oder unterschiedlichen Molekulargewichten einschließen. Um die Pyrrolidone zu bilden, werden die Aminund die Lacton-Reaktanden zusammen in einem Molverhältnis zwischen 1 : 1 und 1 : 5 unter konstantem Rühren bei einer Temperatur zwischen 100°C und 350°C und unter einem Druck zwischen dem Atmosphärendruck und 650 psi für 1 bis 15 Stunden zur Reaktion gebracht; besonders bevorzugt bei 250 °C bis 300°C unter anfänglichem Umgebungsdruck für 5 bis 10 Stunden. Das resultierende Pyrrolidon-Produkt wird durch Destillation oder irgendein anderes geeignetes Wiedergewinnungsverfahren zurückgewonnen und gereinigt.One of the most useful nitrogen-containing surfactants that can be used in combination with the ethoxylated thiol-containing surfactant is one that is derived from N-alkylpyrrolidone. N- (n-alkyl) -2-pyrrolidone, in which the alkyl group contains 6 to 15 carbon atoms, is particularly preferred. This compound is described in US 5,093,031, assigned to ISP Investments, Inc., Wilmington, DE, which discloses surfactants lactams. The above-mentioned N-alkylpyrrolidone products have a molecular weight of 180 to 450 and are suitably made by various known methods, including the reaction between a lactone of the formula

wherein n is an integer from 1 to 3, and an amine having the formula R'-NH ₂ , wherein R 'is a linear alkyl is a group of 6 to 20 carbon atoms. The amine reactant with the formula R'-NH ₂ includes alkylamines having 6 to 20 carbon atoms; Amines derived from natural products, such as coconut amines or talc amines from distilled cuts or hydrogenated derivatives of such fatty amines. Mixtures of amine reactants can also be used in the process for the preparation of the pyrrolidone compounds. Such mixtures may include linear amino species with an alkyl group of the same molecular weight or different molecular weights. To form the pyrrolidones, the amine and lactone reactants are combined in a molar ratio between 1: 1 and 1: 5 with constant stirring at a temperature between 100 ° C and 350 ° C and under a pressure between atmospheric and 650 psi for Reacted for 1 to 15 hours; particularly preferably at 250 ° C to 300 ° C under initial ambient pressure for 5 to 10 hours. The resulting pyrrolidone product is recovered and purified by distillation or any other suitable recovery process.

The N-alkylpyrrolidone products with 11 to 14 carbon atoms are clear, water-bright at room temperature Liquids, whereas those with 16 or more carbon atoms are solids are. These pyrrolidones have a neutral to slightly basic pH, a surface tension between 25 and 35 dynes / cm as a 0.1% solution in water and a viscosity of 6 up to 30 cps at 25 ° C.

In general, the C ₆ to C ₁₄ alkyl pyrrolidones primarily show surface active properties, whereas the C ₁₆ to C ₂₂ alkyl species are primarily complexing agents, although some degree of surface active and complexing properties exist in all of the species present. A particular advantage of alkylpyrrolidone surfactants is the additional detergent property that these surfactants provide for the formulations of this invention.

US 5,093,031 discloses that The inventive compounds control undesirable odors from metal treatments and come from slaughterhouse operations, as well as household smells in carpets, furniture, Clothes and your favorite environment. The surfactants of the Patents are described as compounds that are odor-producing Particles in the waste of animals and humans, for example mercaptan, Urea, tar, nicotine, mold and other odor-causing Contain chemicals that can complex.

The relative amounts of the ethoxylated surfactants Substance and the nitrogenous surfactant are so far not too critical as the amount of nitrogenous surfactants Substance dependent the surface-active used Substance varies. The amount of nitrogenous used surfactants Substance should be such that it has the smell of thiol surfactants Substance reduced, if not eliminated. It will generally assumed that the relative amounts by weight of the ethoxylated thiol-containing surfactants Substance for nitrogenous surface-active substance in the area from 1.0: 0.1 to 1.0: 2.0 and preferably in the range of 1.0: 0.2 should be up to 1: 1. This doesn't mean these ratios strictly limiting the invention and the only relative Amounts of the corresponding surfactants Substances are considered that are used in an effective manner can, and accordingly, it is intended that any appropriate relationship be considered Part of the present invention is considered. Any expedient relationship is a relationship that is enough to remove dirt, grease, oil and other contaminants from the metal surface to remove and that into an aqueous Product that has the unpleasant smell relative to an equivalent preparation reduced in which the ethoxylated thiol-containing substance is present and the nitrogenous surfactant Substance not present.

In addition to the combination of the alkalinity Means and the surfactant Substance as described above excludes the aqueous metal cleaning composition of the present invention preferably a hydrotrope and a polycarboxylate one that the precipitation the water hardness causing salts decreased. In use, the dry Ingredients of the invention provided in the form of a solution in water, wherein the water is preferably demineralized water, or by reverse osmosis treatment is purified water.

The polymeric anti-precipitative Means can kind of as a water soluble Carboxylic acid polymer or a vinyl addition polymer can be categorized. polyacrylates are particularly preferred. Of the vinyl addition polymers contemplated are maleic anhydride copolymers with vinyl acetate, styrene, ethylene, isobutylene, acrylic acid and Preferred vinyl ethers. All of the polymers described above are water soluble or at least colloidally dispersible in water. The molecular weight these polymers can vary widely, although it is preferred to use polymers that have an average molecular weight in Range from 1,000 to 1,000,000. In a preferred one embodiment In this invention, these polymers have a molecular weight of 100,000 or less, and, most preferably, between 1,000 and 10,000.

While Polymers with higher Molecular weight can be used, there is no special one Benefit from using them as they tend to recirculate as a result of the shear forces Cooling systems, too break. Lead further They turn into highly viscous products when in concentrated formulations In larger quantities that are difficult to use.

-Gruppen enthalten, worin M Wasserstoff, Alkalimetall, Ammonium oder ein anderes wasserlösliches Radikal ist. Die Polymere oder Copolymere können entweder durch Addition oder hydrolytische Techniken hergestellt werden. Daher werden die Maleinsäureanhydrid-Copolymere, durch Additionspolymerisation von Maleinsäureanhydrid und einem anderen Comonomer, wie beispielsweise Styrol, hergestellt. Die Acrylsäurepolymere mit niedrigem Molekulargewicht können hergestellt werden durch Additionspolymerisation von Acrylsäure oder deren Salzen, entweder mit sich selbst oder anderen Vinylcomonomeren. Alternativ können solche Polymere hergestellt werden durch alkalische Hydrolyse von Acrylnitril-Homopolymeren oder - Copolymeren mit niedrigem Molekulargewicht. Für solch eine präparative Technik siehe Newman, US-3,419,502.The water-soluble polymers of the type described above are often copolymers which are considered useful in the practice of the present invention provided that they are at least 10% by weight.

- Contain groups in which M is hydrogen, alkali metal, ammonium or another water-soluble radical. The polymers or copolymers can be made by either addition or hydrolytic techniques. Therefore, the maleic anhydride copolymers are made by addition polymerization of maleic anhydride and another comonomer such as styrene. The low molecular weight acrylic acid polymers can be made by addition polymerization of acrylic acid or its salts, either with itself or other vinyl comonomers. Alternatively, such polymers can be made by alkaline hydrolysis of low molecular weight acrylonitrile homopolymers or copolymers. For such a preparative technique, see Newman, U.S. 3,419,502.

As previously stated, maleic anhydride polymers are prefers. Particularly useful Maleic anhydride polymers are chosen from the group consisting of homopolymers of maleic anhydride and Copolymers of maleic anhydride with vinyl acetate, styrene, ethylene, isobutylene, acrylic acid and Vinyl ethers. These polymers can easily manufactured using standard polymerization methods become.

The carboxylated polymer prevents discontinuation due to precipitation of water hardness causative salts during the reaction with the alkaline salts of the cleaning preparations of this invention.

Useful hydrotropes of this invention include sodium, potassium, ammonium and alkanolammonium salts of xylene, toluene, ethylbenzoate, isopropylbenzene, naphthalene, alkylnaphthalenesulfonates, phosphate esters of alkoxylated alkylphenols, phosphate esters of alkoxylated alcohols and sodium, potassium and ammonium Salts of alkyl sarcosinates. The hydrotropes are useful for keeping the surfactant well dispersed in the aqueous cleaning solution and especially in an aqueous concentrate which is a particularly preferred packaging form of the preparations of the invention and which allows the user of the preparations to add the desired amount of cleaning composition to the aqueous Give washing solution. A particularly preferred hydrotrope is one that does not foam. Among the most suitable such hydrotropes are those comprising alkali metal salts of medium chain monocarboxylic fatty acids, i.e. C ₇ -C ₁₃ . Alkali metal octanoates and nonanoates are particularly preferred.

The metal cleaning compositions of this invention comprise 20 to 80% by weight of the alkalinity donor Based on the dry components, 4 to 50% by weight the ethoxylated thiol-containing surfactant, 1 to 30% by weight of the nitrogen-containing surface-active substance, 0 to 10 % By weight of the sedimentation preventing agent and 0 to 30% by weight of the hydrotrope. If the alkaline agent is the preferred Carbonate salt and the preferred bicarbonate salt should be the combination of these Salts are present in an amount of 20 to 80% by weight. If such Mixture is used, the amount of bicarbonate salts should be preferred 5 to 80% by weight and the amount of carbonate salts 5 to 60% by weight include, based on the dry composition. The dry one Composition is in the aqueous wash solution used in amounts of 0.1 to 20 wt .-%, preferably 0.2 to 5 wt .-%. Especially the metal cleaning composition of the present is preferred Invention provided and added to the wash bath as an aqueous Added concentrate, in which the dry components of the composition 5 to 45 % By weight of the concentrate and preferably 5 to 20% by weight of the concentrate include.

The aqueous metal cleaning solutions of present invention are for removing a variety of contaminants of metal substrates useful. In particular, metal substrates comprising engine parts are the with fat and oil are dirty, advantageously using the metal cleaning Composition of this invention and aqueous solutions of such compositions cleaned. A useful procedure for cleaning such metal parts is cleaning in a parts washer. In such parts washer the metal parts with the watery solution contacted, either by immersion or some kind of Exposure in which the watery cleaning solution is continuously circulated or sprayed onto the metal parts. Alternatively, the treatment can be carried out using ultrasound waves. The cleaning solution will then filtered and reusable in the parts washer recycled. It is best to use the watery one cleaning solution this invention increased Have temperature, typically in the range of 32 ° C to 82 ° C. The contact time the watery cleaning solution with the metal substrates, including the metal engine parts, becomes dependent vary in the degree of pollution, and is generally in Range from 1 to 30 minutes, with 3 to 15 minutes more common are.

The metal cleaning compositions of the present invention are useful for removing any type of soiling from metal surfaces, including greases, cutting fluids, draws liquids, machine oils, anti-rust oils, such as cosmolin, coal contaminations, sebum contaminations, solid materials, waxes, paraffins, used motor oil and fuels. Any metal surface can be cleaned, including iron-based metals such as iron, iron alloys, e.g. steel, tin, aluminum, copper, tungsten, titanium, molybdenum. The structure of the metal surface to be cleaned can vary widely and is not limited. Therefore, the metal surface can be a metal part of complex configuration, such as sheets, coils, cylinders, bars, rods, plates and disks. Such metal components can come from any source, including those for domestic and industrial use such as the space industry, the automotive industry, the electronics industry, in which the metal surface needs to be cleaned.

example 1

The following test with a panel was carried out by people to see if the nitrogenous compounds smell a cleaning formulation containing an ethoxylated thiol-containing surfactant Contains substance, would reduce. Table 1 shows formulation (A) and control (B) (without nitrogenous compounds).

Table 1

• 1. acrylic acid polymer, Alco Chemical Co., Chatanooga, TN
• 2. Sodium nonanoate, Mona Industries
• 3. ethoxylated dodecyl mercaptan (6 ethylene oxide units)
• 4. N-alkyl pyrrolidone, ISP

The procedure of the smell panel was as follows. Both solutions were rated at room temperature to be comparable to uncomfortable odors to have. A panel of 6 people was asked to do the comparison Smell B and give it a 7 on a scale of 1 to 10. Then was each member of the panel asked to formulate the sample A smell and the smell of the solution on a scale of 1 to rate 10. Table 2 shows the results.

Table 2

All six members of the panel selected the formulation of the present invention (Sample A) as that which has a less unpleasant smell than comparative sample B.

A second attempt was made in which samples A and B were diluted with water (10 x) and evaluated at 71 ° C were. In this smell test, the comparison formulation became a sample B smelled B and she got a 5 on a scale of 1 to 10 given. Subsequently the formulation of Sample A was sniffed by each member of the panel with an evaluation. Table 3 shows the results the panel's attempt.

Table 3

Again, all five members voted the panel's formulation of Sample A as that with less unpleasant smell than the comparison sample B.

Example 2

In this example, further odor tests were performed to determine whether various nitrogen-containing compounds, including the pyrrolidone compound used in Example 1 and other nitrogen-containing and non-nitrogen-containing compounds, can reduce the unpleasant smell of a cleaning preparation containing the ethoxylated thiol-containing surfactant. A significant reduction in unpleasant smell was determined using a sequential analysis card. Control Sample C had the formulation as shown in Table 4 below. Table 4 Sample C ingredients Wt .-% o DI H ₂ O 81.08 sodium bicarbonate 4.48 potassium carbonate 2.90 sodium 2.22 magnesia 0.074 Carboxylate copolymer ¹ 0.25 Monthrop 1250 6.00 Alcadet 260 3.00

Samples D through I had the same Formulation like the control sample, except that 1.5% of the water have been replaced by the appropriate compound, the was tested for the reduction of the unpleasant smell. Table 5 summarizes the test of six compounds D through I related to the reduction of the unpleasant smell of control.

It can be seen that samples D to G the unpleasant smell of the thioether-containing surface-active Reduce substance significantly. Each of these materials includes one Nitrogen group. On the other hand, the two could be ethoxylated surfactants Substances that do not contain a nitrogen group, the unpleasant No smell of the thioether-containing surfactant significantly reduce.

Example 3

In this example, an aqueous cleaning formulation within the scope of the present invention in terms of cleanability tested and compared to the cleanability of two commercial ones Cleaners and a control that has the equivalent alkalinity as that had inventive formulation, but not the surface-active Substance or other active ingredients included. Table 6 shows sample J, the cleaner of the present invention.

The commercial cleaners were Brulin 815 GD ^® , a phosphate-based cleaner containing a high proportion of surfactant and Daraclean 235 ^® (WR Grace), which contains triethanolamine. Table 6 SAMPLE J Wt .-% Demineralized water 81.910 sodium bicarbonate 4,480 potassium carbonate 2,900 sodium 2,220 magnesia 0.074 BJ 76 ¹ 0,250 sodium nonanoate 3,000 Alcodet 260 3,000 LP 100 1,500

Sample J from Table 6 and the control examples, including of the commercial cleaner, obtained as concentrates, were with Diluted water (10 x) and the solutions were at 71 ° C heated.

It became a pollution mix from 1/3 heavy oils and fats taken from the bottom of a petroleum distillation, 1/3 used engine oil and 1/3 axle grease. About 1 gram of this pollution mixture was on a metal mesh screen applied. The metal mesh screen was immersed in the heated cleaning solution and periodically from this solution removed and weighed to determine the amount of dirt removed determine. The results are shown in the figure in which each the data points represent the mean of three measurements.

As you can see from the figure, led the watery Cleaners of the present invention for significantly improved results after the first minute of cleaning, compared to the alkaline Control and the two commercial products.

Example 4

In a typical commercial Use of the metal cleaning composition of the present Invention is the cleaning solution continuously filtered to remove solid dirt or to separate a phase of pollution and then for reuse recycled. With continuous reuse, the cleaning solution becomes a contain increasing amount of soiling contained in the cleaning solution are. It is appropriate that a commercial cleaning solution can still clean even after repeated use of the solution, although the solution contains a significant amount of contaminants removed from the surface were. This example illustrates the utility of the cleaning composition of the present invention.

In this example the sample J shown in Table 6 above; tested to their ability to determine after repeated treatments to remove contaminants from still cleaning.

There was a pollution mixture from 1/3 heavy oils and fats, taken from the bottom of a petroleum distillate, 1/3 used Engine oil and 1/3 axle grease. About 1 gram of the pollution mixture was applied to a metal mesh screen.

100 ml of the concentrate (sample J), listed in Table 6, were diluted to 1,000 ml with water from the tap (10th x) and at about 71 ° C heated. The metal mesh screen was immersed in the heated cleaning solution for about 3 to 4 minutes and removed to determine the weight of the amount of dirt removed. The oil remaining on the mesh represents the "initially remaining oil" as shown in the table below 7 listed.

64 grams of an oil and 135 grams of a fat bottom obtained by cleaning metal parts were de added to the heated test solution. The amount of impurities added to the solution corresponds to about 4 to 6 weeks of heavy cleaning. The metal meshes were again immersed in the solution for 3-4 minutes, removed and weighed to determine the amount of oil remaining on the meshes. This is the "final oil" as shown in Table 7 below.

The solution was allowed to cool to room temperature and the top oil layer was removed. The solution was then filtered through Celite ^™ . The weight, pH and conductivity of the treated solution were then measured. A prepared solution was then added based on a 1/10 dilution to 1,000 ml with water from the tap and heated to the working temperature. The steps described above represent a cleaning cycle. Six such cleaning cycles were performed and the results of the cleaning are shown in Table 7 below.

Table 7

The addition of the oil crown and the sediment to the cleaning solution each cycle should simulate cleaning for about 20 to 30 weeks. As you can see, the cleanability of the solution during the test maintained.

Example 5

Sample K represents a particularly useful concentrated formulation according to this invention. Table 8 SAMPLE K Wt .-% Demineralized water 79.580 sodium bicarbonate 4,480 potassium carbonate 2,900 sodium 2,220 magnesia 0.074 Carboxylated polymer ¹ 0,250 sodium nonanoate 6,000 Alcodet 260 3,000 LP 100 1,500

Claims (33)

aqueous, metal cleaning composition which provides an alkalinity Agent and a mixture of surfactants with an alkoxylated thiol-containing surface-active substance and a nitrogen-containing one surfactants Has substance. Metal-cleaning composition according to claim 1, characterized in that the alkalinity- providing agent comprises alkali metal carbonates, alkali metal bicarbonates or mixtures thereof. Metal cleaning composition according to one of claims 1 or 2, characterized in that the alkoxylated thiol-containing surface active Substance has 3 to 20 ethylene oxide groups and a reaction product a primary, secondary or tertiary Is alkyl thiols, the alkyl having 6 to 30 carbon atoms Has ethylene oxide. Metal cleaning composition according to claim 3, characterized that the alkoxylated thiol has 7 to 20 carbon atoms and is ethoxylated with 3 to 15 ethylene oxide units. Metal cleaning composition according to one of the preceding Expectations, characterized in that the alkoxylated thiol-containing surface active Substance in the composition in quantities relative to the nitrogenous one surfactants Substance from 1.0: 0.1 to 1.0: 2.0 based on the weight of the corresponding surface-active Substances, is present. Metal cleaning composition according to one of the preceding Expectations, characterized in that the nitrogen-containing surface active Substance is N-alkyl pyrrolidone. Metal cleaning composition according to claim 6, characterized in that the N-alkyl pyrrolidone is formed as N- (n-alkyl) -2-pyrrolidone wherein the alkyl has 6 to 15 carbon atoms. Metal cleaning composition according to one of the preceding Expectations characterized in that it also has a polycarboxylate. Metal cleaning composition according to one of the preceding Expectations, characterized in that it also contains a hydrotropic substance having. Metal cleaning composition according to one of the preceding Expectations, characterized by 20 to 80 weight percent of the alkalinity providing agent; 4 to 50 percent by weight of the alkoxylated thiol surfactants Substance, 1 to 30 weight percent of the nitrogenous surfactant Substance, 0 to 10 weight percent of a polycarboxylate and 0 to 30 percent by weight of a hydrotrope. aqueous, metal cleaning concentrate with 5 to 45 percent by weight of one metal cleaning composition and with balance water, being the metal cleaning composition is an alkalinity and an agent Mixture of surface active Has substances which has an alkoxylated thiol-containing surface-active Has substance and a nitrogenous surfactant. aqueous, metal-cleaning concentrate according to claim 11, characterized in that the alkalinity supplying agents alkali metal carbonate, alkali metal bicarbonate or mixtures thereof. aqueous Cleaning concentrate according to claim 11 or 12, characterized that the metal cleaning composition 20 to 80 weight percent of the alkalinity supplying agent, 4 to 50 weight percent of the alkoxylated thiol-containing surfactants Substance, 1 to 30 weight percent of the nitrogenous surfactant Substance, 0 to 10 weight percent of a polycarboxylate and 0 to 30 percent by weight of a hydrotropic substance. aqueous Cleaning concentrate according to claim 11, 12 or 13, characterized in that that the alkoxylated thiol is an ethoxylated alkyl thiol with 7 to 20 Has carbon atoms and with 3 to 15 ethylene oxide units is ethoxylated. aqueous Cleaning concentrate according to one of the preceding claims 11 to 14, characterized in that the alkoxylated thiol surfactants Substance in the composition in quantities relative to the nitrogenous one surfactants Substance from 1.0: 0.1 to 1.0: 2.0 based on the weight of the corresponding surface-active Substances is present. aqueous Cleaning concentrate according to one of the preceding claims 11 to 15, characterized in that the nitrogen-containing surface active Substance is an N-alkyl pyrrolidone. aqueous Cleaning concentrate according to claim 16, characterized in that the N-alkyl-pyrrolidone is formed as N (n-alkyl) -2-pyrrolidone wherein the alkyl has 6 to 15 carbon atoms. Process for cleaning metal substrates to remove contaminants remove it, leaving the metal substrates with an aqueous cleaning solution be brought into contact which is a metal cleaning composition in water, wherein the metal cleaning composition alkalinity supplying agent and a mixture of alkoxylated thiol-containing and nitrogenous surfactants Has substances, and wherein the metal substrates with the aqueous cleaning solution be contacted for a sufficient time to remove the contaminants to remove from the substrate. Process for cleaning metal substrates according to claim 18, characterized in that the alkaline agent alkali metal carbonate, Has alkali metal bicarbonate or mixtures thereof. Process for cleaning metal substrates according to claim 18 or 19, characterized in that the metal cleaning composition 20 to 80 percent by weight of the alkaline agent, 4 to 50 percent by weight of the alkoxylated thiol-containing surfactant Substance, 1 to 30 weight percent of the nitrogenous surfactant Substance, 0 to 10 weight percent of a polycarboxylate and 0 to 30 of a hydrotropic substance. Process for cleaning metal substrates according to one of the previous claims 18 to 20, characterized in that the alkoxylated thiol ethoxylated alkyl thiol having 7 to 20 carbon atoms and having 3 to 15 ethylene oxide units is ethoxylated. Process for cleaning metal substrates according to one of the previous claims 18 to 21, characterized in that the alkoxylated thiol surfactants Substance in the composition in quantities relative to the nitrogenous one surfactants Substance from 1.0: 0.1 to 1.0: 2.0 based on the weight of the corresponding surface-active Substances is present. Process for cleaning metal substrates according to one of the previous claims 18 to 22, characterized in that the nitrogen-containing surface active Substance is N-alkyl pyrrolidone. Method according to one of the preceding claims 18 to 23, characterized in that the aqueous cleaning solution 0.1 up to 20 percent by weight of the metal cleaning composition contains and a pH greater than 8 and has less than 12. A method according to claim 24, characterized in that the aqueous cleaning solution has a pH of 8 to 10. Method according to one of the preceding claims 18 to 25, characterized in that the metal substrates are metal parts have, wherein the metal parts with the aqueous cleaning solution in a metal parts washing system by immersion, impact or both are brought into contact, after which the metal parts of the cleaning solution be separated and the watery cleaning solution reused in the parts washer to clean other parts becomes. A method according to claim 26, characterized in that the Metal parts with the watery cleaning solution sprayed become. Method according to one of the preceding claims 18 to 27, characterized in that the aqueous cleaning solution Temperature from 32 to 82 ° C (90 to 180 ° F) has, the metal parts with the aqueous cleaning solution for 1 to 30 minutes in contact. Composition of surfactants Substances that have an alkoxylated thiol-containing surfactant Substance with a bad smell and a sufficient amount of a nitrogenous surfactant Has substance to the bad smell to reduce the alkoxylated thiol-containing surfactant. Composition of surfactants Substances according to claim 29, characterized in that the alkoxylated thiol-containing surface-active Substance has 3 to 20 ethylene oxide groups and a reaction product a primary, secondary or tertiary Is alkyl thiols, the alkyl having 6 to 30 carbon atoms Has ethylene oxides. Composition of surfactants Substances according to claim 30, characterized in that the alkoxylated Thiol has 7 to 20 carbon atoms and 3 to 15 ethylene oxide units is ethoxylated. Composition of surfactants Substances according to one of the claims 29, 30 and 31, characterized in that the alkoxylated thiol-containing surfactants Substance in the composition in quantities relative to the nitrogenous one surfactants Substance from 1.0: 0.1 to 1.0: 2.0 based on the weight of the corresponding surface-active Substances is present. Composition of surfactants Substances according to one of the preceding claims 29 to 32, characterized that the nitrogenous surfactant is an N- (n-alkyl) -2-pyrrolidone wherein the alkyl contains 6 to 15 carbon atoms.